Subversion, WebDAV, and Apache HTTP Server 2.0

Transcription

1 Subversion, WebDAV, and Apache HTTP Server 2.0 Justin R. Erenkrantz University of California, Irvine Slides:

2 What is Subversion? Did you miss Subversion: Version Control Rethought? A compelling replacement to CVS was released this morning Expect a release every two-three weeks

3 What is Subversion? Currently alpha Extremely conservative approach Subversion is self-hosting But, don t take our word for it Expect 1.0 soon-ish - beta in 2-3 months

4 What is WebDAV? A mechanism for distributed authoring Specified in RFC 2518 A lot of software now supports WebDAV Forgot about versioning in RFC 2518 DeltaV - RFC 3253 Subversion partially implements DeltaV

5 Overview mod_dav_svn mod_authz_svn Autoversioning ra_svn basics svnadmin basics Bindings and Hooks

6 Subversion + WebDAV Why do what others have done? Portability used by using APR Subversion includes an httpd 2.x module Built on top of mod_dav Can browse repository over HTTP Need WebDAV client to make changes Simply add mod_ssl to use SSL

7 Subversion Remote Access Ways to talk to a repository in Subversion ra_local - Local file-based file:// ra_svn - Custom protocol svn:// or svn+ssh:// ra_dav - WebDAV-based or

8 mod_dav_svn Apache module for Subversion Requires httpd-2.0 (or greater) Uses mod_dav included with 2.0 Use --with-apxs=/path/to/httpd/apxs when configuring Subversion Clients require Neon to use ra_dav client

9 mod_dav_svn/ra_dav Protocol Uses a subset of WebDAV/DeltaV Each file is retrieved via GET Properties retrieved via PROPFIND Transactions done via MKACTIVITY Finally MERGE back See notes/webdav-general-summary

10 mod_dav_svn Example # Must be after mod_dav.so if it exists as a DSO LoadModule dav_svn_module modules/mod_dav_svn.so <Location /svn/repos> DAV svn SVNPath /absolute/path/to/repository </Location> If you want authentication and a group of repositories: <Location /svn/repos> DAV svn SVNParentPath /absolute/path/to AuthType Basic AuthName Subversion repository AuthUserFile /my/svn/user/passwd/file </Location>

11 mod_authz_svn Path-based authorization Allow user Joe to access /joe only Allow group committers write-access Inherit permissions from parent File-based configuration Other RA layers will not use this now!

12 mod_authz_svn Syntax [groups] <groupname> = <user>[,<user>...]... [<path in = [rw r] <user> = [rw r] * = [rw r] * = Everyone r = GET, PROPFIND, REPORT, OPTIONS w = MKCOL, DELETE, PUT, PROPPATCH, CHECKOUT, MERGE, MKACTIVITY... COPY and MOVE require at least w on destination

13 mod_authz_svn Example Add to your Location block: AuthzSVNAccessFile /path/to/access/file Require valid-user /path/to/access/file contains: [groups] branchonly=john,mary,alice writers=bob,jones,scotty [/]

14 Autoversioning Not all clients will be Subversion clients Allows WebDAV-only clients to modify No need for custom clients! Generic log message used on commits <Location /svn/repos> DAV svn SVNPath /absolute/path/to/repository SVNAutoversioning on </Location>

15 Autoversioning Example See subversion/notes/autoversion-compatibility.txt Add to your Location block: SVNAutoversioning On Tested Clients: Nautilus 2.x Windows WebFolders Mac OS X Finder Linux davfs2 Macromedia Dreamweaver DAVExplorer

16 mod_dav_lock Some WebDAV clients are class 2 MacOS X s Finder Require LOCK support from repository Subversion does not have this directly Only httpd 2.1 includes mod_dav_lock Use DavGenericLockDB directive

17 Full configuration example <Location /svn/repos> DAV svn SVNPath /absolute/path/to/repository SVNAutoversioning on DAVGenericLockDB logs/repos-locks AuthType Basic AuthName Subversion repository AuthUserFile /my/svn/user/dir/passwd AuthzSVNAccessFile /my/svn/user/dir/access Require valid-user </Location>

18 ra_svn Not everyone trusts Apache! ra_svn was introduced Allows for tunneling May require local accounts svnserve daemon Anonymous/read-only access

19 ra_svn Tunnels % svn checkout svn+ssh://hostname/usr/local/svn/repository Opens a remote connection Executes svnserve -t on the other end Uses svn+<tunnel> Configured in ~/.subversion/config Default of svn+ssh exist

20 svnadmin Allows for management of repository Recover Backup/Restore Archive Only works with local file access No remote administration yet

21 Subversion and Berkeley DB Built on top of Berkeley DB 4.x All data is stored in Berkeley DB tables Ensures the integrity of the system (ACID) However, may require some maintaining

22 Recovering corrupted database You may see, Need to run recovery Chances are it is not really corrupt Run svnadmin recover /path/to/repos Ensure that there are no open processes httpd, svnserve, etc.

23 Berkeley DB log files Berkeley DB creates log files Allows complete playback Can grow very large Usually, not all log files are needed As of , svnadmin archive cleans up db_archive xargs rm also works

24 Subversion dump format Subversion has its own archive format Plain text format with MIME-like headers Berkeley DB is not really portable If switch endianness, need to recreate Required on repository format updates dump/load cycle

25 svnadmin dump svnadmin dump /path/to/repos Defaults to stdout Options -rx:y - specify ranges to dump --incremental Loading into created repository

26 svnadmin load svnadmin load /path/to/repos Reads from stdin Repository must already be created UUIDs For future distributed repositories Use, ignore, or create on load

27 svndumpfilter Ability to tweak a dump file Reads dump from stdin New file on stdout Exclude or include paths in dump Renumber missing revisions Poor man s svn obliterate

28 Bindings C and SWIG-centric bindings Subversion has lots of little libraries Utilize SWIG to target multiple languages Python is the main supported target Automatically in-sync with C API mailer.py and ViewCVS use SWIG binding

29 Hooks Each repository has a hooks directory Scripts can be placed in there Can be called at various points Server-side only commit: pre-, start-, post- hooks revprop changes: pre-, post-

30 ViewCVS and mailer.py Current development snapshot of ViewCVS supports Subversion Allows viewing of revisions other than the latest one mailer.py Post-commit hook that sends diff s

31 Conclusion Subversion plays well with WebDAV Path-based authorization available Autoversioning allows for non-subversion clients to access the repository svnadmin is an essential tools for admins

32 The Final Word Upcoming O Reilly Book Subversion: The Definitive Guide See Included with Subversion source, too Real-time help: irc.freenode.net #svn Mailing list: [email protected]